The teachings of all of the references cited herein are incorporated herein by reference.
Many disease states are associated with the over-expression of a receptor such as the Her2/Neu receptor in breast cancer or an enzyme such as protein kinase in some cancer. It has been the strategy for sometime to develop small peptide antagonists to these receptors or enzymes, however, the random isolation and screening of polypeptides has been slow and produced relatively few results. Thus there is a need to provide for a rapid method for discovering peptide ligands that bind to and antagonize disease-associated receptors or ligands.